The digital revolution is happening but with the rise of technology impacting every facet of modern life, how much use of iPads, smartphones and other devices is too much use?

Teen Brain author David Gillepsie believes that for teenagers and young adults aged 12 to 22, any use of digital devices could have a detrimental impact on young wellbeing, and he is not alone in his stand against digital usage by children.

The World Health Organisation last month recommended that babies up to 2 never use screens, while for 2, 3 and 4 year the limit was less than one hour a day.

Optometry Australia have warned that Australian children are presenting with digital eye strain and dry eye, a condition normally reserved for adults, leading to eye redness, blurry vision, light sensitivity, eyelid crusting, and a gritty feeling in the eye.

While some experts in the field, following Spanish research, also suggest that blue LED light in digital devices may be causing damage to the retina at the back of the eye in young children, possibly leading to early macular degeneration, cataracts or even blindness.

Quite apart from these physical impacts, Mr Gillepsie talks about the impact that devices are having on teenage brains, and in particular, the software design of social media and entertainment apps.

"We already know that during adolescence, which is the start of puberty from 12 and until 22, a significant and important part of the brain is being built. It is the part that manages our impulses, allows us to assess risk and consequence, and socialise with other human beings," Mr Gillepsie said.

"But in order to develop these impulses the brain turns off a mechanism called GABA, which stands for gamma amino butyric acid, that would normally stop us being addicted to things that we like. When GABA switches off, adolescence becomes a time when the human brain is particularly prone to addiction."

Mr Gillepsie said when adults eat, drink, socialise or have sex the brain is rewarded, neurons become electronically excited, and then GABA kicks in to shut down the reward system.

In teenagers however, GABA does not exist and so the reward keeps on occurring, the neurons continue to be excited, and this process then opens up the brain to addiction.

Mr Gillepsie said this is why teenagers have always been susceptible to risky behaviours such as drugs, alcohol and teenage sex.

But he said the overarching danger is that addiction opened up pathways to depression, anxiety and other mental health issues.

"We know that any addictive behaviour or substance which is set up during adolescence is much more likely to be with a person for their entire life," he said.

"It gets hard wired into their brain at that point so that if you've become a binge drinker when you're 15, you are then twice as likely to be a binge drinker for rest of your life.

"Addiction to one thing makes it much easier to become addicted to other things because the same neural pathways are being set."

Mr Gillepsie said this information was not new, but when applied to the reality that a majority of children and teenagers are exposed to addictive technology on a daily basis, it became highly concerning.

"Teenagers are being handed software which is expressly designed to be addictive, at a time when their brain is least able to deal with it," Mr Gillepsie said.

"We are distributing software explicity engineered for addiction, designed to hook into the way the human brain processes reward.

"And that is the business model. The only way you are going to keep on clicking on Instagram or Facebook is because you are addicted to it, it is designed for people to keep coming back, many times a day."

He added that the younger a child was when handed a device, the harder it would be for parents down the line, to stop or limit the usage.

"A child that is being kept quiet at one is going to find it really, really hard 10 years later when they can't have an iPad anymore. It habituates both the parent and the child as being an acceptable way for child to spend time, and that is bad."

The Australian Bureau of Statistics finds that 99 per cent of young people aged 15 to 17 are online, who spend an average of 18 hours a week on the internet, mostly using it for social networking, entertainment and education purposes.

While numerous studies and reports are conducted in this area, a report by the Royal Childrens Hospital found in 2017 that kids were spending an average of 32 hours on screens at home per week.

Of the 648 preschoolers in the sample a third owned their own device, while more than half of the 1782 primary school aged owned a device, and of these one in six had their own social media accounts.

In response to device overuse, several schools in Tasmania have banned smartphones in classrooms, while in some schools interstate, smartphones are being locked away throughout the school day to prevent idle use of the devices.

Such idle use was found to reduce student attention span, lessen ability to retain information, and lead to a drop in academic performance. Mr Gillepsie believes that a ban of smartphones in schools is not the answer, due to phones now being an important means of communication.

"Almost every school requires students to have iPads or some kind of device for homework, or to complete other schoolwork. Schools have ensured that this addictive software is in the hands of every child, and are becoming the unwitting distributors for the software giants," he said.

"My advice is to go old school. Treat devices like an-old school desktop. Require them to be in a simple, obvious and open place within the family home, attached to the wall, and do not permit usa of devices in bedrooms.

Kids will still use devices at school or on the bus, but it is about minimising the potential for addiction."

He said parents should always remember that children are not adults, and that even those with a perceived good judgement are at risk.

"They look, behave and sound like adults but they do no have an adult brain," he said.